Donath Landsteiner Antibody
Paroxysmal cold hemoglobinuria (PCH) is a rare form of autoimmune hemolytic anemia. It was characteristically associated with syphilis in the past, but nowadays is more often associated with acute viral infections. PCH can also present as an idiopathic cold hemagglutinin syndrome. The autoantibody that causes this syndrome is called the Donath Landsteiner antibody. It is also referred to as a biphasic cold hemolysin, because it binds to red blood cells only at cold temperatures and causes complement mediated hemolysis only after warming to body temperature. The autoantibody often has specificity for the P blood group antigen.
The test is performed by drawing two tubes of blood. One is immediately incubated at 37o C for one hour. The second tube is immediately incubated in an ice bath for 30 minutes and then transferred to a 37o C water bath for an additional 30 minutes. Both tubes are then centrifuged and examined for hemolysis. If the serum of the tube incubated in the cold is hemoglobin-tinged and the serum of the tube that remained at 37o C is clear, the patient has a Donath Landsteiner antibody. If both the cold and warm incubated tubes are hemolyzed, no conclusion can be drawn about the presence of a Donath-Landsteiner antibody.
Reference value is a negative result.
Specimen requirement is two 4-mL pediatric red top tubes immediately incubated in an ice bath and a 37o C water bath.
